Climate change could hit Rogue Valley hard

If global warming continues unabated, summer temperatures in the Rogue River Valley could rise up to 15 degrees by 2080, making the weather in the southern Oregon valley similar to Sacramento's, Oregon researchers said in a report released today.

The study's authors used the global Intergovernmental Panel on Climate Change's "business as usual" scenario to make the projections. That scenario assumes that most countries fail to act to reduce greenhouse gas emissions.

Bob Doppelt, director of the leadership initiative, noted that atmospheric carbon levels are already above the IPCC's estimates from last year for the business-as-usual scenario. And temperature increases are likely even under best-case scenarios, he said.

"We wanted to paint the picture of the likely consequences of climate change if there is no change" in society's response, Doppelt said. "Even if the effect in the valley is half of that or a third of that, it's pretty significant. It's already hot down there in the summer."

The Rogue River Valley, beginning near Crater Lake and running to Gold Beach, has 302,000 residents. It's considered a powerhouse system for wild salmon, and its whitewater runs draw tourists from around the globe.

The researchers, with help from a U.S. Forest Service bioclimatologist, applied three global climate change models to the valley. In those models, the global forecasts are more certain than regional ones, particularly regarding precipitation, but Doppelt said the general trends should hold. Among their findings:

Average annual temperatures will increase by 1 to 3 degrees by 2040 and 4 to 8 degrees by 2080. Summer temperatures could increase dramatically, rising 7 degrees to 15 degrees by 2080.

Snow accumulation could decline by 25 to 75 percent by 2040, and up to 94 percent by 2080, reducing summer streamflows, water quality and water supply. Big winter storms and rainfall could increase, boosting flooding.

A longer summer with higher temperatures will likely increase wildfires and could create lethal stream conditions for native fish such as salmon and steelhead, similar to conditions on the lower Klamath River during the 2002 fish kill.

The report says local governments, businesses and homeowners need to start taking the effects of global warming into account now. That includes politically tough and potentially expensive measures such as restricting development in wildfire-prone areas and floodplains, restructuring timber harvests, setting aside more habitat and restoring more streams.